tests/test_general.py:test_3081(): avoid problems on Windows.

On Windows renaming to an existing file never works, so have removed those
parts of the test. We still check explicitly that the file handles are closed,
so the test is still doing what we want.

tests/test_general.py

@@ -863,17 +863,3 @@ def next_fd():
     assert fd2 == fd1 + 1
     assert fd3 == fd1
     assert fd4 == fd1
-
-    # Check copying/renaming to file we have opened; this is mainly for Windows
-    # where renames fail if destination is open.
-    #
-    document = fitz.open(path2)
-    document.close()
-    shutil.copy2(path1, path2)
-    print(f'{document=}')
-
-    document = fitz.open(path2)
-    document.close()
-    shutil.copy2(path1, path3)
-    os.rename(path3, path2)
-    print(f'{document=}')